The technology of electronic autostereoscopic displays, usually involving flat panels, has advanced to the point where it is now viable for many applications. Dedicated autostereoscopic displays are available, but there are computer users who want the ability to move between planar applications, such as word processing, and stereoscopic visualization applications, and still obtain a clear image for both types of applications. There are some technologies which allow for dual mode monitors that function in either an autostereoscopic mode or planar mode, but not in both modes simultaneously.
For displays using a lenticular (or raster barrier) selection device, a significant problem is that the refractive properties of the lens sheet fragments distorts small point type and fine-resolution image elements such as desktop icons, task bars, and drop-down menus. Thus, with the lens sheet in place, the autostereoscopic monitor can typically not be used to simultaneously view both stereoscopic information and fine type or icons. Many approaches have been previously considered to address this problem. For example, a display utilizing an overlay such as a lenticular screen has been described in co-pending U.S. patent application Ser. No. 09/943,890, entitled AUTOSTEREOSCOPIC LENTICULAR SCREEN. With the lenticular ridges facing inward towards the flat panel surface, a chamber is created between the flat panel surface and the lenticular ridges to hold a liquid that is emptied to provide 3-D viewing and filled to defeat the refraction properties of the screen.
U.S. Pat. No. 5,500,765, entitled CONVERTIBLE 2D/3D AUTOSTERESCOPIC DISPLAY discloses a display having a lenticular overlay in close contact with the flat panel front surface, but with the ridges facing outward. To defeat the lenticular “refractive” characteristics, a mating inverse lenticular screen is placed atop the lenticular screen in proper alignment so that the overlaid screen will negate the refraction of the original.
Another approach is to fabricate a removable lenticular screen that is held firmly in precision alignment when placed in intimate juxtaposition with the flat panel display.
Another approach, described in press releases by Sharp and DTI technologies, involves the use of a liquid crystal modulator in proper proximity to the imaging display surface. The modulator is made up of rulings that can be turned on and off to transition between a raster barrier and a clear cover sheet. When in the raster barrier mode, a stereoscopic image can be observed. This is well-known art and therefore not described herein. However, it is of interest to note that from an optical standpoint, lens sheets and raster barriers are more or less interchangeable, and information prepared for one can be displayed using the other. Therefore, although the inventive technique disclosed herein is described with reference to lenticular sheets, it also applies in principal to the raster barrier selection device technique.
Whatever the merits of these two-state approaches (stereo and planar), they do not solve the essential problem of enabling the user to clearly see some areas of the display screen autostereoscopically and some areas in the planar mode. In this disclosure, a means for simulataneously displaying both stereoscopic and planar information in selected areas of the display is revealed.